It is common practice for commercial property owners to require roof-top inspections at suitable intervals of flat roofs having roof drains. When properly conducted, such inspections followed by diligent removal of accumulated ice and debris prevent the drains from becoming blocked, so that water is allowed to drain away before it does damage. Inspections are required both during construction of the building, and during the useful life of the building.
A significant problem arising when conducting these inspections is that roof-drains can become invisible when covered by either wind-blown leaves during the fall season, or when even moderate amount of snow accumulate during the winter. Quite often, inspectors find themselves walking around the roof-top on its ice-covered, snow-covered, or leaf-covered surfaces, not entirely sure whether or not they have found all of the roof-drains on that particular roof. Also, searching ice-covered roof-tops is, by its nature dangerous. So inspectors often find themselves guessing where the drains might be, based on prior experiences with similar commercial roofs. This is especially true when a roof is covered with six or more inches of snow. Such difficulties leave much room for error. Many drains are not found. Roof-drains that are not found are not inspected, and consequently are not cleared.
The lack of a roof-drain inspection can be catastrophic. When roof-drains are not cleared of ice and debris after a snow storm, the snow that melts during the day deposits water onto areas of the roof where it is not meant to collect. Water that does not drain properly refreezes. This causes damage to roof seams and prior roof repairs. Such damage causes various kinds of roof leaks. In foreseeable worst-case scenarios, a roof can become so compromised with damage that it becomes a safety hazard, posing such dangers as falling ceiling tiles, full ceiling collapse, partial roof collapse, and even collapse of a complete roof. Thus, failure to reliably find, inspect and clear every roof-drain on the roof of a large building can cause significant physical damage to the building. Such risks can justify high insurance premiums. Such risks can also constitute a breach of public safety resulting in law suits. Even worse than physical damage to a building, or incurring financial loss, collapse of a complete roof can cause people in or on the building to suffer serious injury or death.